Catholic University, following in the footsteps of other Washington-area colleges, has decided to raise its tuition by 8.7 percent for most undergraduate and graduate students next fall and by even more for architecture, engineering and law students.

The new increases, which come on top of hefty tuition boosts that were imposed for the current school year, will raise the basic tuition from $5,750 to $6,250 a year for undergraduate and graduate students.

Tuition for Catholic University's law students will increase 9.8 percent, from $6,100 to $6,700, while the tuition for the university's architecture and engineering students will go up by 10.4 percent, from $5,750 to $6,350.

The university's board of trustees, which approved the increases Saturday, boosted tuition last year by 17.4 percent for undergraduate students and by 12.8 percent for graduate students.

With the latest tuition increases, the university estimates that with room and board and other expenses it will cost its 7,000 students a total of $10,950 apiece to attend the Northeast Washington school next year.

A university spokesman said the tuition boost was necessary because of increased operating costs, plans for improvements in various programs and faculty salary increases. University provost John J. Murphy noted that "Even with this latest increment, the percentage of tuition increase is lower than at other area universities."

Georgetown University last week increased its undergraduate tuition by 12 percent to $7,650 for next fall.

Earlier, George Washington University raised tuition by 24.5 percent to $6,100, while American University approved a 12.9 percent boost to $7,000 and Trinity College a 9.2 percent increase to $5,900.

The University of Maryland plans to increase next fall's tuition by 13 percent, to $1,128 for in-state students and to $3,523 for out-of-staters.

George Mason University will raise its tuition by about 17 percent for the next school year, to $1,380 for in-state students and $2,664 for out-of-state students.